Agaricus bisporus white button mushroom (WBM) is widely consumed in most countries for its culinary properties. Recently, its dietary intake has been shown to protect against breast cancer. Mushroom ...polysaccharides are known for their immunomodulating and antitumor properties; however, little is known regarding the properties of A. bisporus polysaccharides. Using size-exclusion chromatography to fractionate the crude extract of A. bisporus, two polysaccharide fractions (designated as ABP-1 and ABP-2) were obtained. The estimated molecular masses of ABP-1 and ABP-2 were 2,000 kDa and 40-70 kDa, respectively, and their sugar compositions consisted mainly of glucose, mannose, xylose, and fructose. Analysis of the effects of the polysaccharides on murine macrophages demonstrated that both fractions stimulated the production of nitric oxide, interleukin-6, and tumor necrosis factor-α. Modulation of macrophage function by A. bisporus polysaccharides was mediated in part through activation of nuclear factor-κB with the production p50/105 heterodimers. Both ABP-1 and ABP-2 had the ability to inhibit the growth of human breast cancer MCF-7 cells but had little effect on the growth of human colon, prostate, gastric cancer, and murine Sarcoma 180 cells as assessed by a tetrazolium dye 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide-based assay. However, when murine Sarcoma 180 cells exposed to ABP-1 or ABP-2 were implanted subcutaneously into mice, a reduction in tumor growth was observed compared with that observed in control mice. Taken together, our data provide a molecular basis to explain in part the reported beneficial therapeutic effects of A. bisporus WBM intake and suggest that macrophages likely contribute to the antitumor effects of Agaricus polysaccharides.
Enrichment of vitamin D2 in Agaricus bisporus white button mushroom (WBM) using continuous UV light needs a longer exposure time, which can lead to discoloration. Using a Xenon pulsed UV light ...source, the yield of vitamin D2 was evaluated in freshly harvested button mushrooms and mushroom slices after exposure to 2.5, 3, 6 and 9 pulses of UV light at an average dose of 1.150J/cm2 energy per pulse. Increase in vitamin D2 content was proportionate to the number of pulses of UV light. There was no difference in the vitamin D2 content of mushrooms between 200g and 500g punnets for the corresponding number of pulses (737±81, 847±38, 1148±182, 1611±444% versus 747±48, 911±35, 1307±109, 2028±181% Daily Value/serving, respectively; P>0.05). Mushrooms in the top layer showed significantly higher amounts of vitamin D2 content than those in the bottom layer of a 500g punnet (657±22, 796±76, 1433±138, 1878±178% versus 129±60, 237±117, 403±35, 830±257% DV/serving, respectively; P<0.01). A single layer of sliced mushrooms (∼5mm thick) showed higher amounts of vitamin D2 content than sliced mushrooms packaged together after pulsed UV light exposure (7882±1074, 6867±944, 10,826±472, 13,001±1635% versus 1221±281, 1293±210, 1598±207, 2018±459% DV/serving, respectively; P<0.001). Discoloration of whole or sliced mushrooms was not observed. Thus, pulsed UV light provides a highly effective method for increasing vitamin D2 levels in A. bisporus white button mushroom.
Abstract Objective Secretory immunoglobulin A (SIgA) acts as the first line of adaptive humoral immune defense at mucosal surfaces. A lack of SIgA or the inability to produce antigen-specific SIgA ...can lead to an increased risk of infections. Dietary intake may improve mucosal immunity by accelerating SIgA secretion. This study investigated the effect of dietary intake of Agaricus bisporus white button mushroom (WBM) on salivary IgA (sIgA) secretion in healthy subjects. Methods Twenty-four healthy volunteers were randomly assigned to a normal daily diet (control group) or a normal diet with WBM. The subjects in the active group ( n = 12, 41.4 ± 11.3 y old) consumed 100 g of blanched WBM daily with their normal diet for 1 wk, whereas those in the control group consumed their normal diet ( n = 12, 43.5 ± 12.5 y old) without WBM. Saliva was collected before and after commencement of the study and every week thereafter for 3 wk. Saliva flow rate, sIgA concentration, and osmolality were determined and the sIgA:osmolality ratio and the sIgA secretion rate were calculated. Results There was no significant difference between pre- and postdietary mushroom intakes for all indices in the control group ( P > 0.05). In contrast, the mean sIgA secretion rate increased significantly at weeks 1 and 2 by 53% and 56%, respectively, compared with that at week 0 ( P < 0.0005) in the WBM intake group and then returned to a baseline level at week 3. Changes in sIgA secretion rate over the intervention period were greater in the WBM group than in the control group without WBM. In both groups, no significant changes in osmolality and saliva IgG were noted. There was, however, a significant increase in the sIgA:osmolality ratio ( P < 0.0012), confirming the postdietary WBM-induced sIgA increase. Conclusion The dietary intake of A. bisporus WBM significantly accelerates sIgA secretion, thereby indicating its potential health benefits for improving mucosal immunity.
Analysis of vitamin B12 in freshly harvested white button mushrooms (Agaricus bisporus) from five farms was performed by affinity chromatography and HPLC-ESI-MS techniques. The vitamin B12 ...concentrations obtained varied from farm to farm, with higher concentrations of vitamin B12 detected in outer peel than in cap, stalk, or flesh, suggesting that the vitamin B12 is probably bacteria-derived. High concentrations of vitamin B12 were also detected in the flush mushrooms including cups and flats. HPLC and mass spectrometry showed vitamin B12 retention time and mass spectra identical to those of the standard vitamin B12 and those of food products including beef, beef liver, salmon, egg, and milk but not of the pseudovitamin B12, an inactive corrinoid in humans. The results suggest that the consumer may benefit from the consumption of mushroom to increase intake of this vitamin in the diet.
Effective eradication of Helicobacter pylori (H. pylori) infection has often proved more difficult than expected. Antimicrobial resistance incompletely explains eradication failure. This study tests ...the hypothesis that an impaired immune response may contribute to failed eradication after standard antibiotic therapy.
Parameters of host immunity were assessed as blood T lymphocyte production of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) being surrogate markers of mucosal Th1 and Th2 responses, respectively. The validity of using circulating T cell cytokines as surrogate markers of mucosal immunity was established (unstimulated lymphocyte IL-4 level correlation r2 = 0.549, p < 0.001; antigen-stimulated lymphocyte correlation r2 = 0.62, p < 0.001).
A total of 52 dyspeptic patients and 11 patients with previous H. pylori eradication failure were recruited into the study. There was no significant difference in secretion of IFN-gamma from peripheral blood T cells, in either unstimulated or antigen-stimulated cultures, between clinical groups. There was, however, a significant reduction in secretion of IL-4 from blood T cells in subjects failing to eradicate H. pylori compared with those who successfully eradicated the infection in both unstimulated and stimulated cultures. A significant difference in IL-4 secretion was also detected in antigen-stimulated cultures compared with that in H. pylori-positive subjects (p < 0.05). Low levels of IL-4 secretion were detected irrespective of the number of courses of antibiotic therapy. Lower levels of IgG anti-H. pylori antibody were detected in both serum and saliva of subjects with persistent H. pylori infection after use of antibiotics compared with untreated H. pylori-positive subjects (difference not statistically significant).
These results support the hypothesis that impaired mucosal immunity, particularly involving the secretion of IL-4, may contribute to H. pylori eradication failure. Measurement of whole blood secretion of IL-4 may predict which patients are more likely to fail standard antibiotic therapy.
Candida albicans is a common opportunistic pathogen, causing both superficial and systemic infection. Clinical observations indicate that mucocutaneous infections are commonly associated with ...defective cell‐mediated immune responses, whereas systemic infection is more frequently seen in patients with deficiencies in neutrophil number or function. Analysis of mechanisms of host resistance against gastrointestinal and oral infection in mouse models has demonstrated an absolute dependence on CD4+ T cells, although clearance also involves phagocytic cells. Both IL‐12 and TNF‐α appear to be important mediators, but mouse strain‐dependent variations in susceptibility to infection may be related to T‐cell enhancement of production of phagocytic cells by the bone marrow. In murine systemic infection, the role of innate and adaptive responses is less well defined. Studies in immunodeficient and T‐cell‐depleted mice suggest that clearance of the yeast may be predominantly a function of the innate response, whereas the adaptive response may either limit tissue damage or have the potential to cause immunopathology, depending on the host genetic context in which the infection takes place.
Abstract Agaricus bisporus (white button mushroom; WBM) contains high levels of dietary fibers and antioxidants including vitamin C, D, and B12 ; folates; and polyphenols that may provide beneficial ...effects on cardiovascular and diabetic diseases. The objective of this study was to examine the hypothesis that intake of the fruiting bodies of WBM regulates anticholesterolemic and antiglycemic responses in rats fed a hypercholesterolemic diet (0.5% cholesterol; 14% fat) and rats with type 2 diabetes induced by injection of streptozotocin (STZ) (50 mg/kg body weight), respectively. The STZ-induced diabetic male Sprague-Dawley rats fed the Agaricus bisporus powder (ABP; 200 mg/kg of body weight) for 3 weeks had significantly reduced plasma glucose and triglyceride (TG) concentrations (24.7% and 39.1%, respectively), liver enzyme activities, alanine aminotransferase and aspartate aminotransferase (11.7% and 15.7%, respectively), and liver weight gain ( P < .05). In hypercholesterolemic rats, oral feeding of ABP for 4 weeks resulted in a significant decrease in plasma total cholesterol (TC) and low-density lipoprotein (LDL) (22.8% and 33.1%, respectively) ( P < .05). A similar significant decrease in hepatic cholesterol and TG concentrations was observed (36.2% and 20.8%, respectively) ( P < .05). Decrease in TC, LDL, and TG concentrations was accompanied by a significant increase in plasma high-density lipoprotein concentrations. It was concluded that A bisporus mushroom had both hypoglycemic and hypolipidemic activity in rats.
Summary
A murine model of oral candidiasis was used to show that nitric oxide (NO) is involved in host resistance to infection with Candida albicans in infection‐‘resistant’ BALB/c and ...infection‐‘prone’ DBA/2 mice. Following infection, increased NO production was detected in saliva. Postinfection samples of saliva inhibited the growth of yeast in vitro. Treatment with NG‐monomethyl‐l‐arginine (MMLA), an inhibitor of NO synthesis, led to reduced NO production, which correlated with an increase in C. albicans growth. Reduction in NO production following MMLA treatment correlated with an abrogation of interleukin‐4 (IL‐4), but not interferon‐γ (IFN‐γ), mRNA gene expression in regional lymph node cells. Down‐regulation of IL‐4 production was accompanied with an increase in IFN‐γ production in infection‐‘prone’ DBA/2 mice. There was a functional relationship between IL‐4 and NO production in that mice treated with anti‐IL‐4 monoclonal antibody showed a marked inhibition of NO production in saliva and in culture of cervical lymph node cells stimulated with C. albicans antigen. The results support previous conclusions that IL‐4 is associated with resistance to oral candidiasis and suggest that NO is involved in controlling colonization of the oral mucosal surface with C. albicans.
Agaricus bisporus mushrooms contain an abundance of ergosterol, which on exposure to UV irradiation is converted to vitamin D2. The present study evaluated the effects UV-C irradiation on vitamin D2 ...formation and its bioavailability in rats. Fresh button mushrooms were exposed to UV-C irradiation at mean intensities of 0.403, 0.316, and 0.256 mW/cm2 from respective distances of 30, 40, and 50 cm for periods ranging from 2.5 to 60 min. Vitamin D2 and ergosterol were measured by HPLC-MS/MS. The stability and retention of vitamin D2 were assessed including the extent of discoloration during storage at 4 °C or at room temperature. Exposure to UV-C irradiation at 0.403 mW/cm2 intensity from 30 cm distance resulted in a time-dependent increase in vitamin D2 concentrations that was significantly higher than those produced at intensities of 0.316 and 0.256 mW/cm2 from distances of 40 and 50 cm, respectively. Furthermore, the concentrations of vitamin D2 produced after exposure to UV-C irradiation doses of 0.125 and 0.25 J/cm2 for, 2.5, 5, and 10 min were 6.6, 15.6, and 23.1 μg/g solids, equivalent to 40.6, 95.4, and 141 μg/serving, respectively. The data showed a high rate of conversion from ergosterol to vitamin D2 at short treatment time, which is required by the mushroom industry. The stability of vitamin D2 remained unchanged during storage at 4 °C and at room temperature over 8 days (P = 0.36), indicating no degradation of vitamin D2. By visual assessment or using a chromometer, no significant discoloration of irradiated mushrooms, as measured by the degree of “whiteness”, was observed when stored at 4 °C compared to that observed with mushrooms stored at room temperature over an 8 day period (P < 0.007). Vitamin D2 was well absorbed and metabolized as evidenced by the serum response of 25-hydroxyvitamin D in rats fed the irradiated mushrooms. Taken together, the data suggest that commercial production of button mushrooms enriched with vitamin D2 for improving consumer health may be practical.
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